Process for the recovery of copper from its sulfide ores

ABSTRACT

An improvement in the process for recovering copper from its sulfide ores or concentrates thereof which comprises treating the ore with cupric chloride and/or ferric chloride to form a copper chloride electrolyte and a residue, electrolytically recovering copper from the electrolyte and further treating the residue with ferric chloride to solubilize substantially all of the copper remaining therein for conversion to copper chloride electrolyte, with ferrous chloride from the electrolyte being regenerated to ferric chloride for leaching the residue, the improvement which comprises conducting the electrolysis without the conversion of any cuprous copper to cupric copper, using a separator between the anolyte and catholyte compartments of the electrolytic cell to prevent passage of ions of copper and iron between the catholyte and anolyte, continuously further treating the residue with regenerated ferric chloride of a concentration to insure there is no cuprous copper in the resulting solution and regenerating ferric chloride from ferrous chloride in the solution free of cuprous chloride by passing the solution through the anolyte compartment of the electrolytic cell as copper is continuously being recovered at the cathode of the cell.

United States Patent [191 Kruesi et al.

[451 Aug. 26, 1975 PROCESS FOR THE RECOVERY OF COPPER FROM ITS SULFIDEORES [75] Inventors: Paul R. Kruesi; Duane N. Goens,

both of Golden, C010.

[73] Assignee: Cyprus Metallurgical Processes Corporation, Los Angeles,Calif.

22 Filed: Nov. 14, 1974 21 Appl.No.:523,S88

Primary ExaminerRi L. Andrews Attorney. Agent, or FirmSheridan, Ross &Fields [57] ABSTRACT An improvement in the process for recovering copperFEED from its sulfide ores or concentrates thereof which comprisestreating the ore with cupric chloride and/or ferric chloride to form acopper chloride electrolyte and a residue, electrolytically recoveringcopper from the electrolyte and further treating the residue with ferricchloride to solubilize substantially all of the copper remaining thereinfor conversion to copper chlo ride electrolyte, with ferrous chloridefrom the electrolyte being regenerated to ferric chloride for leachingthe residue, the improvement which comprises conducting the electrolysiswithout the conversion of any cuprous copper to cupric copper, using aseparator between the anolyte and catholyte compartments of theelectrolytic cell to prevent passage of ions of copper and iron betweenthe catholyte and anolyte, continuously further treating the residuewith regenerated ferric chloride of a concentration to insure there isno cuprous copper in the resulting solution and regenerating ferricchloride from ferrous chloride in the solution free of cuprous chlorideby passing the solution through the anolyte compartment of theelectrolytic cell as copper is continuously being recovered at thecathode of the cell.

RECYCLE Cu TH ICKENER FILTERS REDUCTIOWTHOLYEI ANODES CATHODES PRODUCTIZCELL cmooss] I F8203 I FQCI;

Fe CELL MS PATENTEDAUGZSISWS 3,901,776

FEED

ammo

RECYCLE Cu LEACH V FILTERS REDUCTION CATHOLYTE I THICKENER ANODESCATHODES r r LEACH 2 THICKENER I I PR T THICKENER ANODES CATHODES CugwflLEACH 3 7 THICKENER THICKENER a ANODES CATHODES Cu"- FILTERS THICKENER cQ r\ V TAILS ALTERNATE -PURIF|CAT|ON I I Fe 0 I V l HYDROLYSIS Fe CELLcATHooEs I I F8203 |FeC| Fe CELL ANODES Fecla PROCESS FOR THE RECOVERYOF COPPER FROM ITS SULFIDE ORES BACKGROUND OF THE INVENTION 1. Field ofthe Invention The invention relates to hydrometallurgical processes forrecovering copper from its sulfide ores in which the sulfide sulfur isrecovered as elemental sulfur so that the sulfur dioxide pollutionproblem characteristic of pyrometallurgical processes is eliminated.Particularly, the invention is related to those processes wherein thecopper in copper sulfide is solubilized by treating the ore with cupricchloride and/or ferric chloride with the copper being recovered from theresulting copper chloride solution by electrolysis. The present processresults in the recovery of high yields of commercial grade copper witheconomic consumption of power in the electrolysis step due to animprovement by which no cuprous copper is converted to cupric copperduring electrolysis and the anode of the cell is utilized for theconversion of ferrous chloride from spent ferric chloride leach solutionto ferric chloride for further leaching while substantially all of thecopper is being continuously plated from the electrolyte.

2. Prior Art As is well known. the main source for copper today iscopper sulfide ores. principally, chalcopyrite. Conventionalpyrometallurgical processes by which the copper was formerly recoveredfrom its sulfide ores are objectionable today because of the pollutingeffect of the sulfur dioxide produced by these processes. Accordingly.there is a great deal of activity in the copper industry to developpollution-free processes for the recovery of copper from its sulfideores.

A large number of hydrometallurgical processes are being developed inwhich the copper in its sulfide ores is solubilizcd by treatment of theore with ferric chloride and/or cupric chloride with the formation ofelemental sulfur followed by recovery of the copper from the resultingsolution or electrolyte by electrolysis. The sulfur dioxide pollutionproblem is eliminated in these processes in which the sulfide sulfur isconverted to elemental sulfur.

The steps for solubilizing copper in chalcopyrite usually include theprocedure of first reacting the raw ore with cupric chloride followed byfurther reaction of the resulting solution with a reducing agent such asmetallic copper to provide an electrolyte which is essentially allcuprous chloride. The residue from the cupric chloride reaction step isthen treated with ferric chloride to soluhilize essentially all of theremaining copper. in order for these processes to be commerciallyfeasible, they must be highly efficient in the consumption of electricalenergy. regeneration of reagents. removal of impurities. recovery ofother metals contained in the ore. and they must not generateundesirable amounts of sulfate ions with the consequent prohibitiveconsumption of electrical energy or reagents.

It is well known that for the economic recovery of copper byelectrolysis the copper in the electrolyte must he in the cuprous form.It is also well known that the presence of ferric or cupric ions at thecathode where copper is being plated from cuprous chloride interfereswith the plating of the copper. An expedient to keep these ions awayfrom the cathode is the use of a separator to prevent the circulation ofelectrolyte from cathode to anode as the plating is in progress. Another(ill expedient is to avoid the presence of ferric ions in the anolyte byleaving enough cuprous copper in the electrolyte for oxidation to cupriccopper to prevent any oxidation of ferrous ion to ferric ion as thefirst oxidation has precedence over the latter. This procedureeliminates ferric ions in the electrolyte which might travel to thecathode, but it also requires circulation of the electrolyte fromcathode to anode or some other procedure to prevent cupric ions fromcoming in the vicinity of the cathode. An objection to the latterprocedure is, of course, that large amounts of copper are beingrecirculated in a continuous process when only a portion of the copperentering the cell is being recovcred.

In these procedures in which electrolysis is performed on an electrolyteresulting from initially leaching the copper sulfide ores with ferricchloride and/or cupric chloride. the ferrous chloride entering the cellin the electrolyte passes on through the cell unaffected and isconventionally oxidized to ferric chloride in the spent electrolyte andthe resulting ferric chloride recirculated to leach chalcopyrite residuefrom the initial cupric chloride leaching step. Ordinarily, only oneeffective leaching can be performed with the recirculated ferricchloride without regeneration as it is substantially reduced to ferrouschloride in the leaching of the chalcopyrite residue. An efficient meansutilizing the electrolytic cell for regenerating the ferric chlorideafter leaching the chalcopyrite residue for further leaching of residueis desirous. In accordance with this invention a process is provided bywhich the anode of the electrolytic cell is used to regenerate spentferric chloride from chalcopyrite residue leaching while copper is beingcontinuously recovered at the cathode in the absence of ferric andcupric ions.

US. Pat. No. 333,8l5 discloses an electrolytic process for the recoveryof copper from ferric chloride leach solutions of copper sulfide ores inwhich ferric chloride is regenerated at the anode. However, this processis performed with cuprous ions in the presence of the anode and wouldobviously be inefficient to regenerate ferric chloride because of theprecedence of the oxidation of cuprous to cupric ions over the oxidationof ferrous to ferric ions. Also, no procedure is provided for preventingcupric and ferric ions from contacting the cathode of preventing theconversion of cuprous to cupric ions during the cell operation.

US. Pat. No. 3,767,543 discloses the regeneration of ferric chloridefrom ferrous chloride at the anode as copper is being electrolyticallyrecovered at the cathode from a ferric chloride leach solution ofchalcopyrite. However. since cuprous ions are present in the anolyte aninefficient regeneration of ferric chloride will result. Further. noprovision is made to prevent the conversion of cuprous to cupric ions.

US. Pat. Nos. 3,764,490 and 3.776.826 both disclose the conversion ofcuprous to cupric copper at the anode and the processes of these patentsare not concerned with the regeneration of ferric chloride from ferrouschloride at all as ferric chloride is not used in leaching the coppersulfide ores.

US. Pat. No. 3.785.944 discloses a process in which copper inchalcopyrite is initially solubilized by treat ment with cupric chlorideand/or ferric chloride with ferric chloride being used to treat residuefrom the initial treatment of the chalcopyrite ore concentrate. Anelectrolyte is produced in a second reduction stage with metallic copperin which essentially all of the copper is reduced to cuprous chlorideand the iron reduced to ferrous chloride. The only regeneration offerric chloride is by oxidation of the ferrous chloride in the spentelectrolyte. the resulting ferric chloride being used to oxidizechalcopyrite residue from the initial cupric chloride treatment of thechalcopyrite concentrate. The patent teaches against the formation offerric chloride at the anode and to prevent this only a portion ofcopper is recovered from the cuprous chloride ClCCll'tY lyte with enoughbeing left in solution for the express purpose of preventing theoxidation of ferrous to ferric chloride at the anode. Electrolyte iscirculated from cathode to anode to prevent the cupric chloride beingformed at the anode from contacting the cathode where copper is beingplated from cuprous chloride electrolyte. The process does not providefor regeneration of ferric chloride in the cell and is expressly dLrected to the conversion of cuprous ions to cupric ions duringelectrolysis.

Accordingly. the principal object of this invention is to provide animprovement in the step for electrolytically recovering copper fromcuprous chloride electrolyte produced by treatment of chalcopyrite oreswith metal chlorides by which efficient utilization of the cell isobtained by using the anode to regenerate ferric chloride from spentferric chloride leach solution while copper is being simultaneouslyplated at the cathode of the cell cuprous chloride electrolyte withoutthe conversion of cuprous ions to cupric ions.

BRIEF SUMMARY OF THE INVENTION In accordance with the invention, finelyground chalcopyrite ore concentrate is treated with cupric chloride in afirst leaching step followed by separation of the solution andchalcopyrite residue. The copper in the solution is further reduced withmetallic copper or other reducing agent to provide an electrolyte inwhich the copper is essentially all in the cuprous form. The electrolyteis subjected to electrolysis in an electrolytic cell in which the anodeand cathode compartments are separated by a separator which preventspassage of ions of iron and copper from the cathode to anode. The spentelectrolyte goes to purification for recovery of the metals other thancopper followed by electrolytic recovery of iron. with simultaneousregeneration of ferric chloride at the anode. An alternative procedureat this point is the removal of excess iron by hydrolysis with oxidationof ferrous chloride to ferric chloride for re circulation. Theregenerated ferric chloride in both instances is circulated to leachingand the spent ferric chloride leach solution is circulated through theanode of the cell as copper is being plated at the cathode forregeneration of ferric chloride for use in further leaching. The resultis that all of the copper can be recovered from the electrolyte withoutthe conversion of cuprous to cupric ions with simultaneous use of thecathode for plating copper and the anode to regenerate ferric chloridefor multiple leachings with overall effective utilization of electricalenergy.

BRIEF DESCRIPTION OF THE DRAWING The single drawing is a flow diagram ofthe process of the invention.

DESCRlPTlON OF THE PREFERRED EMBODIMENTS Referring to the flow diagram.feed of chalcopyrite ore concentrate ground to an average particle sizepreferably 90% 200 mesh is subjected to a cupric chlo' ride leach inleach l. The leaching solution may or may not contain ferric chloride.The reactions between chalcopyrite and ferric chloride and cupricchloride are as follows:

4FeCL, CuFeS- CuCl SFeCI- 28 3CuCl CuFeS 4CuCl FeCL; 25 12 The solidsare separated as chalcopyrite residue and the solution subjected to areduction stage with recycled copper from the electrolysis in whichcupric chloride is reduced to cuprous chloride in accordance with thefollowing reaction.

(u-i-CuCl 2CuCl (3! The solution containing ferrous chloride andsubstantially all of the copper as cuprous chloride is introduced intothe cathode compartment of an electrolytic cell for recovery of copper.The ferrous chloride is not affected by the electrolysis and passes onthrough the cell in the spent electrolyte.

The electrolytic cell is provided with a separator between the anode andcathode separating it into anolyte and catholyte compartments. Theseparator used prevents ions of copper and iron from travelling from thecathode to the anode. The separator also prevents the direct flow ofcatholyte to anolyte or vice versa. An example of a suitable membrane isa microporous polypropylene film sold under the trademark CELGARD" bythe Celanese Plastics Company. Newark. NJ.

The electrolyte is about 2.5 molar in ferrous chloride at a pH of 0.5. Acell temperature of about 80C is used. An anode current density of about80-120 amps per sq. ft. and a cathode current density of about 50-100amps per sq. ft. are used. Some of the copper recovered at the cathodeis recycled to the reduction stage for reducing cupric to cuprouschloride. These are preferred but not limiting process limitations.

Sulfate ion is removed from the electrolyte after electrolysis byprecipitation with barium or calcium in the purification step. Theelemental sulfur formed in leach l is separated with the solids and iseventually removed in the tails from which it is recovered by aconventional procedure.

As will be seen from the flow diagram. the chalcopyrite residue fromleach l is subjected to two leaching steps. that is. leach 2 and leach3. This is done to insure that substantially all of the copper isremoved from the chalcopyrite concentrate. Solution from leach 2containing some copper is continuously recirculated to leach I. Leach 3is performed with ferric chloride resulting from oxidation of ferrouschloride in the spent electrolyte. The spent ferric chloride leachsolution from leach 3 is not recirculated to leach l but is passedthrough the anode compartment of the cell for conversion of the ferrouschloride therein to ferric chloride. This solution entering the anodecompartment is substantially depleted of ferric chloride which will havebeen converted to ferrous chloride in the oxidation of the chalcopyriteresidue from leach 2. The cuprous copper present is oxidized to cupricchloride before the solution enters the anode. The chalcopyrite residuereceived in leach 3 from leach 2 is heavily depleted in copper. Theprocess is operated so that leach 3 will always he conducted with asubstantial excess of ferric chloride so that all of the copper in thechalcopyrite will be completely solubilized and no copper will be lostin the tails. The reaction is preferably conducted at a temperaturebetween l()5l 10C The leach solution entering leach Bfrom leach 2 withresidue will contain some cuprous ions in addition to ferrous and cupricions. However. as leach 3 is done with a substantial excess of ferricion the following reaction occurs:

FeCl CuCl FeCl CuCl (4 The result is that the solution leaving leach 3for the anode contains substantially all of the iron as ferrous ironwith some little ferric iron. and all of the copper as cupric chloridewith no cuprous chloride being present. This is essential for theeconomical conversion of ferrous chloride to ferric chloride at theanode as the oxidation of cuprous to cupric chloride takes precedenceover the oxidation of ferrous to ferric chloride and if any cuprousCopper is present it will be oxidized to cupric chloride before anyferrous chloride will be oxidized to ferric chloride and this willsubstantially diminish the efficiency of the cell in converting ferrouschloride to ferric chloride.

As a precautionary measure, not more than about 859? of the ferrouschloride is oxidized to ferric chloride at the anode because it isadvisable to always maintain some ferrous chloride in the solution sothat if the cell operation is upset at any time there will always besome ferrous ion at the anode for conversion of ferric ion to keep thecell from discharging oxygen or chlorine.

The solution leaving the anode for leach 2 preferably contains not morethan about 85% ferric chloride, l5'71 ferrous chloride and the remaindercupric chloride. This means that the solution is high in ferric chloridefor effective leaching in leach 2 of the chalcopyrite residue from thereduction step. Reactions 1 and 2 above occur in leach 2. The solutionfrom leach 2, which is recirculated to leach 1, contains ferrouschloride plus some cupric and cuprous ions.

In leach l the solution containing ferrous, cuprous and some cupric ionsis contacted with fresh feed so that reaction 2 above occurs. Thus mostof the cupric ions are reduced to cuprous ions. However. Chalcopyrite isinsufficiently active to reduce all of the cupric ion present to cuprousion so that the solution overflowing the first stage thickener containsferrous plus cuprous ions plus some cupric ions. Since it is requiredthat the cupric ions in the solution from leach 1 be at a minimum duringelectrolysis. the solution is contacted with recycled copper powder toreduce the remaining cupric ions to cuprous ions in accordance withequation 3 above. The result is that the solution which becomes theelectrolyte contains iron and copper almost exclusively as ferrous andcuprous ions.

At the cathode copper powder is plated in three stages. The copper fromstage I is product copper and may be sold as such or further refined forsale. Copper further depleted from the electrolyte in electrolyticstages 2 and 3 may be recycled to the reduction stage for the reductionof cupric ion. The electrolyte depleted in copper is sent to thepurification stage where sulfate ion is removed as explained above.

In the purification stage. the last residue of copper and undesiredimpurities such as zinc, lead. arsenic. antimony bismuth. etc, areremoved from spent electrolyte which then proceeds either to ironplating or hy drolysis as shown in the flow diagram.

if the solution is sent to iron plating iron is plated at the cathodefor sale. The iron plating cells are equipped with the same separatorsas the copper plating cells thereby preventing the mixing of catholyteand anolyte and preventing migration of ferric ions from the anolyte tothe catholyte The depleted (anion) catholyte goes to the anode of theiron cell where ferrous iron is oxidized to ferric iron which iscirculated to leach 3.

If the solution is sent to hydrolysis as an alternate procedure. thepurified ferrous solution is treated with oxygen to regenerate ferricchloride and precipitate hydrated iron oxide in accordance with thefollowing equation:

3FeCl 0.75 O Fe Q, 2FeCl s The ferric chloride formed is then circulatedto leach 3.

Based on the chemical reactions of the process set forth above and theuse of the separator between anolyte and catholyte it is apparent thatthere is no possibility for the conversion ofcuprous to cupric ions inthe electrolytic cell. No cuprous ions from the catholyte reach theanolyte to be converted to cupric ions as the separator prevents thetravel of cuprous ions from cath olyte to anolyte. In order todemonstrate that no cuprous ions are introduced into the anolyte fromleach 3, and to demonstrate the efficient conversion of ferrous ionsfrom leach 3 to ferric ions with economical use of electrical powerduring cell operation the following procedure was carried out using theflow sheet of the invention with the results given below being obtained.All percentages are given as weight percentages.

LEACH 3 Partially reacted chalcopyrite residue from leach 2 gave thefollowing analysis:

Two hundred grams of the above residue entered Leach 3 where thesolution from the cathode operation also entered after purification andregeneration. One liter of this purified solution which contained mainlyferric chloride in excess I 182 g/l Fe) encountered the reacted residuefor a thorough leach. The leaching operation of Leach 3 was aimed at acomplete depletion of the copper in chalcopyrite to produce tails readyto be discarded. The leaching was performed at lUfiC and at pH 0.5.

it was found that the system allowed no possibility of formation ofcuprous ions, the solution leaving Leach 3 having the followinganalysis:

The overall recovery of copper after Leach 3 is shown by the followingmetallurgical balance:

(upper in Copper (upper in 91' Copper Feed Soluhili/ed Tails LeachingRecovery 104 g 103.5: g (ms g 99.54

Cell Anode Conversion The cell anode received from the thickeneroverflow of Leach 3 a clear solution with composition as indicatedabove. The cell anode was operated at [20 ampcres per square foot ofgraphite anode area. At total power input of 27 ampere-hours was usedfor the anodic oxidation of ferrous ion to ferric ion at 75C.

It was found that 54.9 grams of iron in ferric form was produced throughanodic oxidation of ferrous iron. The rate of power consumption was 0.49ampere-hours per gram of Fe processed. This FlGURE compared with 0.48ampere-hours per gram Fe** (Fe to Fe***) theoretical. The currentefficiency for the process was 98 percent.

After completing the desired anodic reaction the solution with thefollowing composition was advanced to leach 2:

in g/l 0 l5 2 g/l (1 As stated previously. it is preferred not tooxidize all of the ferrous ion to ferric ion in the cell operation.

LEACH 2 I4 in 71'; 14.7";

The leach liquor from Leach 2 was advanced to Leach l as an overflowfrom thickener 2.

LEACH l The fresh feed of chalcopyrite with head assay of:

(rosy/r was contacted with leach liquor from Leach 2. through thickener2 which contained essentially ferrous. cuprous and some cupric ions withthe following analysis:

its Fe" u 120 g/l The leach was conducted at 80C and at ph 0.5. Thisleach produced the partially reacted chalcopyrite which entered Leach 2with the composition indicated earlier (see Leach 2 for the partiallyreacted chalcopy rite analysis). As shown in the flow sheet. the leachliquor was filtered and advanced to the cathode operation whereby thesolution contacted recycled copper powder from the cathode during thereduction process to reduce cupric to cuprous copper. As a result thesolution entered the cathode as catholytc bearing mainly ferrous andcuprous ions.

From the above data it is seen that the process of the flow sheetoperates with no cuprous ions being converted to cupric ions in the celloperation and with the use of the anode of the cell to convert ferrouschloride in spent ferric chloride leach solution to ferric chloride.with economical consumption of electrical power as copper is beingplated at the cathode.

The process is not restricted to any particular number of electrolysisof leach stages, as more or less than the three stages of each used forillustrating the invention can be utilized. The spent ferric chloridefrom any leaching stage can be sent to the anolyte for regeneration solong as all of the copper in it is in the cuprous stage. Each of theleaching stages may contain any number of leaching steps.

From the above description of the invention. it will he noted that theadvantage provided is that the cell anode can be used for regenerationof ferric chloride while copper is being simultaneously plated at thecathode. The advantage of this is that the ferric chloride regeneratedin the spent electrolyte can be used for a number of oxidation stepswith regeneration to insure complete removal of copper from thechalcopyrite concentrate. the additional oxidation steps being possiblebecause of regeneration of the ferric chloride between steps in theanode of the cell. It is obvious that this is much more economical thanusing oxygen in separate oxidation steps for continued oxidation of thespent ferric chloride leach solution from Leach 3 to regenerate ferricchloride.

Although the invention has been disclosed with the Lise of cupricchloride alone in Leach I, it includes the use ol ferric chloride.()thcr rcductants than metallic copper can he used to reduce the cupricchloride to cuprous chloride in the reduction stage. Any excess sull'atcions gcneratcd in the electrolysis process can be removed from the spentelectrolyte by precipitation with barium or calcium. The process can beconducted with multiple stages ol cells and may be conducted batch orcontinuous.

While the invention has been illustrated by its appli cation tochalcopyrite. a common copper sulfide mineral. it is equally applicableto other copper sulfide minerals. such as. covellite and chalcocite.

What is claimed is:

l. A process for the recovery of copper from Copper sulfide ores andtheir concentrates comprising:

a. leaching the ore or concentrate feed with a material comprisingcupric chloride in a first leaching stage with separation of the solidsfrom the resulting solution and sending the solids to a second leachingstage:

b. reducing substantially all of the copper chloride content of thesolution from said first leaching stage to cuprous chloride;

c. recovering copper from the solution of step (b) by subjecting thesolution to electrolysis in the cath ode compartment of an electrolyticcell having an anode and a cathode and a separator therebetween to keepions of copper and iron from travelling from the cathode to the anode.with the ferrous chloride ions in the cathode unaffected by theelectrolysis;

d. leaching the solids from said first leaching stage with materialscomprising ferric chloride and cupric chloride with separation of thesolids and spent leach solution and sending the latter to saidtfirstleaching stage and the solids to a third leaching stage;

e. oxidizing the ferrous chloride in the spent catholyte from saidelectrolysis to ferric chloride and sending the ferric chloride to saidthird leaching stage to leach the solids from said second leaching stagefollowed by separation of the resulting solids and spent leach solution.and

. introducing the spent leach solution of step (e) containing ferrous.ferric and cupric chlorides into the anode compartment of said cell tooxidize said ferrous chloride to ferric chloride with the cupricchloride being unaffected by the electrolysis. and transferring saidelectrolytically oxidized solution to said second leaching stage;whereby the electrolytic cell is operated without the conversion of anycuprous ions to cupric ions.

2. The process of claim I in which the solution from said second leachis returned to leach (I 3. The process of claim 1 performed as acontinuous process.

4. The process of claim 1 performed in multiple steps and stages.

5. The process of claim I in which in step (b) the reduction isperformed with metallic copper.

6. The process of claim 1 in which the leaching materials in step (a)include ferric chloride.

7. The process of claim I in which in step (f) up to about 8571 of theferrous chloride is oxidized to ferric chloride.

8. In the process for recovering copper from copper sulfide ores ortheir concentrates in which the ore or concentrate is leached withcupric chloride and/or ferric chloride, the resulting solution andresidue separated. substantially all of the copper chloride in thesolution reduced to cuprous chloride, the resulting cuprous chloridesolution electrolyzed to recover copper, and the ferrous chloride in thespent electrolyte oxidized to ferric chloride which is recycled forleaching at least part of the chalcopyrite residue, the improve mentwhich comprises: conducting said electrolysis in an electrolytic cellhaving an anode and a cathode divided by a separator to keep ions ofcopper and iron from travelling from the cathode to the anode. torecover substantially all of the copper in solution at the cathodewithout the formation of eupric copper in the cell.

9. The improved process of claim 8 including solubilizing at least apart of the copper in said residue with said recycled ferric chloride toproduce cupric chloride and ferrous chloride in solution. introducingsaid latter solution into the anode compartment of said electrolyticcell to oxidize the ferrous chloride therein to ferric chloride asmetallic copper is being simultaneously recovered at the cathode andusing the ferric chloride regenerated by the clectrolytie oxidation offerrous chloride in the anode to leach additional chalcopyrite residue.

10. The improved process of claim 9 in which up to about of the ferrouschloride in solution is converted to ferric chloride in the anodecompartment.

1. A process for the recovery of copper from copper sulfiDe ores andtheir concentrates comprising: a. leaching the ore or concentrate feedwith a material comprising cupric chloride in a first leaching stagewith separation of the solids from the resulting solution and sendingthe solids to a second leaching stage; b. reducing substantially all ofthe copper chloride content of the solution from said first leachingstage to cuprous chloride; c. recovering copper from the solution ofstep (b) by subjecting the solution to electrolysis in the cathodecompartment of an electrolytic cell having an anode and a cathode and aseparator therebetween to keep ions of copper and iron from travellingfrom the cathode to the anode, with the ferrous chloride ions in thecathode unaffected by the electrolysis; d. leaching the solids from saidfirst leaching stage with materials comprising ferric chloride andcupric chloride with separation of the solids and spent leach solutionand sending the latter to said first leaching stage and the solids to athird leaching stage; e. oxidizing the ferrous chloride in the spentcatholyte from said electrolysis to ferric chloride and sending theferric chloride to said third leaching stage to leach the solids fromsaid second leaching stage followed by separation of the resultingsolids and spent leach solution, and f. introducing the spent leachsolution of step (e) containing ferrous, ferric and cupric chloridesinto the anode compartment of said cell to oxidize said ferrous chlorideto ferric chloride with the cupric chloride being unaffected by theelectrolysis, and transferring said electrolytically oxidized solutionto said second leaching stage; whereby the electrolytic cell is operatedwithout the conversion of any cuprous ions to cupric ions.
 2. Theprocess of claim 1 in which the solution from said second leach isreturned to leach (1).
 3. The process of claim 1 performed as acontinuous process.
 4. The process of claim 1 performed in multiplesteps and stages.
 5. The process of claim 1 in which in step (b) thereduction is performed with metallic copper.
 6. The process of claim 1in which the leaching materials in step (a) include ferric chloride. 7.The process of claim 1 in which in step (f) up to about 85% of theferrous chloride is oxidized to ferric chloride.
 8. IN THE PROCESS FORRECOVERING COPPER SULFIDE ORES OR THEIR CONCENTRATES IN WHICH THE ORE ORCONCENTRATE IS LEACHED WITH CUPRIC CHLORIDE AND/OR FERRIC CHLORIDE, THERESULTING SOLUTION AND RESIDUE SEPARATED, SUBSTANTIALLY ALL OF THECOPPER CHLORIDE IN THE SOLUTION REDUCED TO CUPROUS CHLORIDE, THERESULTING CUPROUS CHLORIDE SOLUTION ELECTROLYZED TO RECOVER COPPER, ANDTHE FERROUS CHLORIDE IN THE SPENT ELECTROLYTE OXIDIZED TO FERRICCHLORIDE WHICH IS RECYCLED FOR LEACHING AT LEAST PART OF THECHALCOPYRITE RESIDUE, THE IMPROVEMENT WHICH COMPRISES: CONDUCTING SAIDELECTROLYSIS IN AN ELECTROLYTIC CELL HAVING AN ANODE AND A CATHODEDIVIDED BY A SEPARATOR TO KEEP IONS OF COPPER AND IRON FROM TRAVELLINGFROM THE CATHODE TO THE ANODE, TO RECOVER SUBSTANTIALLY ALL OF THECOPPER IN SOLUTION AT THE CATHODE WITHOUT THE FORMATION OF CUPRIC COPPERIN THE CELL.
 9. The improved process of claim 8 including solubilizingat least a part of the copper in said residue with said recycled ferricchloride to produce cupric chloride and ferrous chloride in solution,introducing said latter solution into the anode compartment of saidelectrolytic cell to oxidize the ferrous chloride therein to ferricchloride as metallic copper is being simultaneously recovered at thecathode and using the ferric chloride regenerated by the electrolyticoxidation of ferrous chloride in the anode to leach additionalchalcopyrite residue.
 10. The improved process of claim 9 in which up toabout 85% of the ferrous chloride in solution is converted to ferricchloride in the anode compartment.